40,356 research outputs found
Future Trends of Virtual, Augmented Reality, and Games for Health
Serious game is now a multi-billion dollar industry and is still growing steadily in many sectors. As a major subset of serious games, designing and developing Virtual Reality (VR), Augmented Reality (AR), and serious games or adopting off-the-shelf games to support medical education, rehabilitation, or promote health has become a promising frontier in the healthcare sector since 2004, because games technology is inexpensive, widely available, fun and entertaining for people of all ages, with various health conditions and different sensory, motor, and cognitive capabilities. In this chapter, we provide the reader an overview of the book with a perspective of future trends of VR, AR simulation and serious games for healthcare
Reduced chromosome aberration complexity in normal human bronchial epithelial cells exposed to low-LET γ-rays and high-LET α-particles
This article is made available through the Brunel Open Access Publishing Fund.Copyright © 2013 The Author(s). Purpose: Cells of the lung are at risk from exposure to low and moderate doses of ionizing radiation from a range of environmental and medical sources. To help assess human health risks from such exposures, a better understanding of the frequency and types of chromosome aberration initially-induced in human lung cell types is required to link initial DNA damage and rearrangements with transmission potential and, to assess how this varies with radiation quality.
Materials and methods: We exposed normal human bronchial lung epithelial (NHBE) cells in vitro to 0.5 and 1 Gy low-linear energy transfer (LET) γ-rays and a low fluence of high-LET α-particles and assayed for chromosome aberrations in premature chromosome condensation (PCC) spreads by 24-color multiplex-fluorescence in situ hybridization (M-FISH).
Results: Both simple and complex aberrations were induced in a LET and dose-dependent manner; however, the frequency and complexity observed were reduced in comparison to that previously reported in spherical cell types after exposure to comparable doses or fluence of radiation. Approximately 1–2% of all exposed cells were categorized as being capable of transmitting radiation-induced chromosomal damage to future NHBE cell generations, irrespective of dose.
Conclusion: One possible mechanistic explanation for this reduced complexity is the differing geometric organization of chromosome territories within ellipsoid nuclei compared to spherical nuclei. This study highlights the need to better understand the role of nuclear organization in the formation of exchange aberrations and, the influence three-dimensional (3D) tissue architecture may have on this in vivo.Department of Health, UK (Contract RRX115)
Spread of Infectious Diseases with a Latent Period
Infectious diseases spread through human networks.
Susceptible-Infected-Removed (SIR) model is one of the epidemic models to
describe infection dynamics on a complex network connecting individuals. In the
metapopulation SIR model, each node represents a population (group) which has
many individuals. In this paper, we propose a modified metapopulation SIR model
in which a latent period is taken into account. We call it SIIR model. We
divide the infection period into two stages: an infected stage, which is the
same as the previous model, and a seriously ill stage, in which individuals are
infected and cannot move to the other populations. The two infectious stages in
our modified metapopulation SIR model produce a discontinuous final size
distribution. Individuals in the infected stage spread the disease like
individuals in the seriously ill stage and never recover directly, which makes
an effective recovery rate smaller than the given recovery rate.Comment: 6 pages, 3 figure
Enhancement of superconducting transition temperature by the additional second neighbor hopping t' in the t-J model
Within the kinetic energy driven superconducting mechanism, the effect of the
additional second neighbor hopping t' on the superconducting state of the t-J
model is discussed. It is shown that t' plays an important role in enhancing
the superconducting transition temperature of the t-J model. It is also shown
that the superconducting-state of cuprate superconductors is the conventional
Bardeen-Cooper-Schrieffer like, so that the basic Bardeen-Cooper-Schrieffer
formalism is still valid in quantitatively reproducing the doping dependence of
the superconducting gap parameter and superconducting transition temperature,
and electron spectral function at point, although the pairing
mechanism is driven by the kinetic energy by exchanging dressed spin
excitations.Comment: 8 pages, 4 figures, added discussions and references, accepted for
publication in Physics Letters
Effect of linear energy transfer (LET) on complexity of alpha-particle-induced chromosome aberrations in human CD34+ cells.
The aim of this study was to assess the relative influence of linear energy transfer (LET) of α-particles on chromosome aberration complexity in the absence of significant other track structure differences. To do this we irradiated human haemopoietic stem cells (CD34+) with The aim of this study was to assess the relative influence of linear energy transfer (LET) of α-particles of various incident LET values (110 - 152 keV/µm, with mean LETs through the cell of 119 – 182 keV/µm) at an equi-fluence of approximately 1 α-particle/cell and assayed for chromosome aberrations by m-FISH. Based on a single harvest time to collect early division mitosis , complex aberrations were observed at comparable frequencies irrespective of incident LET, however when expressed as a proportion of the total exchanges detected, their occurrence was seen to increase with increasing LET. Cycle analysis to predict theoretical DNA double strand break rejoining cycles was also carried out on all complex chromosome aberrations detected. By doing this we found that the majority of complex aberrations are formed in single non-reducible cycles that involve just 2 or 3 different chromosomes and 3 or 4 different breaks. Each non-reducible cycle is suggested to represent ‘an area’ of finite size within the nucleus where double strand break repair occurs. We suggest that local density of damage induced and proximity of independent repair areas within the interphase nucleus determine the complexity of aberration resolved in metaphase. Overall, the most likely outcome of a single nuclear traversal of a single α-particle in CD34+ cells is a single chromosome aberration per damaged cell. As the incident LET of the α-particle increases, the likelihood of this aberration being classed as complex is greater
Interplay between single particle coherence and kinetic energy driven superconductivity in doped cuprates
Within the kinetic energy driven superconducting mechanism, the interplay
between the single particle coherence and superconducting instability in doped
cuprates is studied. The superconducting transition temperature increases with
increasing doping in the underdoped regime, and reaches a maximum in the
optimal doping, then decreases in the overdoped regime, however, the values of
this superconducting transition temperature in the whole superconducting range
are suppressed to low temperature due to the single particle coherence. Within
this superconducting mechanism, we calculate the dynamical spin structure
factor of cuprate superconductors, and reproduce all main features of inelastic
neutron scattering experiments in the superconducting-state.Comment: 7 pages, 3 figures, typo correcte
Thermal effects on lattice strain in hcp Fe under pressure
We compute the c/a lattice strain versus temperature for nonmagnetic hcp iron
at high pressures using both first-principles linear response quasiharmonic
calculations based on the full potential linear-muffin-tin-orbital (LMTO)
method and the particle-in-cell (PIC) model for the vibrational partition
function using a tight-binding total-energy method. The tight-binding model
shows excellent agreement with the all-electron LMTO method. When hcp structure
is stable, the calculated geometric mean frequency and Helmholtz free energy of
hcp Fe from PIC and linear response lattice dynamics agree very well, as does
the axial ratio as a function of temperature and pressure. On-site
anharmonicity proves to be small up to the melting temperature, and PIC gives a
good estimate of its sign and magnitude. At low pressures, hcp Fe becomes
dynamically unstable at large c/a ratios, and the PIC model might fail where
the structure approaches lattice instability. The PIC approximation describes
well the vibrational behavior away from the instability, and thus is a
reasonable approach to compute high temperature properties of materials. Our
results show significant differences from earlier PIC studies, which gave much
larger axial ratio increases with increasing temperature, or reported large
differences between PIC and lattice dynamics results.Comment: 9 figure
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